A huge marine mammal known as Steller’s sea cow once lived in the waters around Bering Island off the coast of Siberia. It was described in 1741 by Georg W. Steller, a naturalist who was among the first European to see one. In 1768 the animal became extinct. The reasons for the extinction are not clear. Here are three theories about the main cause of the extinction. First, the sea cows may have been overhunted by groups of native Siberian people. If this theory is correct, then the sea cow population would have originally been quite large, but hundreds of years off too much hunting by the native people diminished the number of sea cows. Sea cows were a good source of food in a harsh environment, so overhunting by native people could have been the main cause of extinction. Second, the sea cow population may have become extinct because of ecosystems disturbances that caused a decline in their main source of food, kelp (a type of sea plant). Kelp populations respond negatively to a number of ecological changes. It is possible that ecological changes near Bering island some time before 1768 caused a decrease of the kelp that the sea cows depend on. Third, the main cause of extinction of the sea cows could have been European fur traders who came to the island after 1741. It is recorded that the fur traders caught the last sea cow in 1768. It thus seems reasonable to believe that hunting by European fur traders, who possessed weapons that allowed them to quickly kill a large number of the animals, was the main cause of the sea cow’s extinction.
题目音频：
play
00:00/02:37听力原文
搜索英文单词
搜索英文单词
搜索英文单词
In this set of materials both the reading and the lecture discus the reasons that cause extinxtion of sea cow. While the reading states that their is three theories explain the extinction of this animal and provides three supportive reasons. The lecture refutes this claims by saying that we do not know the reasons behind the extinction and there are problems with each theory and opposes each and every reason stated by the writer. First, the reading claims tha increase hunting of this animal by native people leaads to extinction of them specially their species was enormous before many years ago. On the other hand, the lecture argues this by mention that the sea cow is massive creature in their size and give some measurement for them and native people at that time were small populations. In turn, they did not need to hunt huge amount of sea cow to feed these small population.
Secondly, the reading makes the arguments that ecosystem disturbance is one of the possible theory that explain extinction because it effect negatively kelp9the food material of sea cow. The lecture counters this by pointing out that if ecosystem is the cause of extinction should in turn, effects all marine animals not only sea cow. Furthermore, the professor adds that ship did not report any reduction of other animals like wheals and also kelp was grow fineand never effected by any changes in ecosystem.
Lastly, the reading argues that European hunters did hunt sea cow for tradingpurposes and creat special weopen eventually. The lecturerefutes this claims by mention that sea cow poplualtion was large by the time of European traders. Furthermore, the professor says that serious cause of extinction not due to hunting them by European but due to other cause which is the main reason for this extinction and not European lastly arrival.
- Do you agree or disagree with the following statement?For the successful development of a country, it is more important for a government to spend money on the education of very young children (five to ten years old) than to spend money on universities. Us 76
- people today spend more time on personal enjoyment doing things they like to do rather than doing things they should do 66
- Agree or disagreeSuccessful leader should take quick decision because taking time in decision may affect people they lead. 70
- Do you agree or disagree with the following statement? Movies and television have more negative effects than positive effects on the way young people behave. Use specific reasons and examples to support your answer. 86
- Some people believe that when busy parents do not have a lot of time to spend with their children, the best use of that time is to have fun playing games or sports. Others believe that it is best to use that time doing things together that are related to 61
Grammar and spelling errors:
Line 1, column 142, Rule ID: THEIR_IS[1]
Message: Did you mean 'there'?
Suggestion: there
... sea cow. While the reading states that their is three theories explain the extinctio...
^^^^^
Line 2, column 135, Rule ID: IT_VBZ[1]
Message: Did you mean 'effects'?
Suggestion: effects
...eory that explain extinction because it effect negatively kelp9the food material of se...
^^^^^^
Line 2, column 453, Rule ID: BEEN_PART_AGREEMENT[1]
Message: Consider using a past participle here: 'grown'.
Suggestion: grown
...r animals like wheals and also kelp was grow fineand never effected by any changes i...
^^^^
Transition Words or Phrases used:
also, but, first, furthermore, if, lastly, second, secondly, so, while, on the other hand
Attributes: Values AverageValues Percentages(Values/AverageValues)% => Comments
Performance on Part of Speech:
To be verbs : 10.0 10.4613686534 96% => OK
Auxiliary verbs: 2.0 5.04856512141 40% => OK
Conjunction : 11.0 7.30242825607 151% => OK
Relative clauses : 13.0 12.0772626932 108% => OK
Pronoun: 30.0 22.412803532 134% => Less pronouns wanted
Preposition: 38.0 30.3222958057 125% => OK
Nominalization: 15.0 5.01324503311 299% => Less nominalizations (nouns with a suffix like: tion ment ence ance) wanted.
Performance on vocabulary words:
No of characters: 1529.0 1373.03311258 111% => OK
No of words: 307.0 270.72406181 113% => OK
Chars per words: 4.98045602606 5.08290768461 98% => OK
Fourth root words length: 4.18585898806 4.04702891845 103% => OK
Word Length SD: 2.53552882206 2.5805825403 98% => OK
Unique words: 155.0 145.348785872 107% => OK
Unique words percentage: 0.504885993485 0.540411800872 93% => More unique words wanted or less content wanted.
syllable_count: 466.2 419.366225166 111% => OK
avg_syllables_per_word: 1.5 1.55342163355 97% => OK
A sentence (or a clause, phrase) starts by:
Pronoun: 1.0 3.25607064018 31% => OK
Article: 9.0 8.23620309051 109% => OK
Subordination: 1.0 1.25165562914 80% => OK
Conjunction: 0.0 1.51434878587 0% => OK
Preposition: 3.0 2.5761589404 116% => OK
Performance on sentences:
How many sentences: 12.0 13.0662251656 92% => OK
Sentence length: 25.0 21.2450331126 118% => OK
Sentence length SD: 37.1266600826 49.2860985944 75% => OK
Chars per sentence: 127.416666667 110.228320801 116% => OK
Words per sentence: 25.5833333333 21.698381199 118% => OK
Discourse Markers: 7.41666666667 7.06452816374 105% => OK
Paragraphs: 3.0 4.09492273731 73% => More paragraphs wanted.
Language errors: 3.0 4.19205298013 72% => OK
Sentences with positive sentiment : 6.0 4.33554083885 138% => OK
Sentences with negative sentiment : 3.0 4.45695364238 67% => OK
Sentences with neutral sentiment: 3.0 4.27373068433 70% => OK
What are sentences with positive/Negative/neutral sentiment?
Coherence and Cohesion:
Essay topic to essay body coherence: 0.126364607442 0.272083759551 46% => OK
Sentence topic coherence: 0.0576003508605 0.0996497079465 58% => OK
Sentence topic coherence SD: 0.0337681671513 0.0662205650399 51% => OK
Paragraph topic coherence: 0.0961236591922 0.162205337803 59% => OK
Paragraph topic coherence SD: 0.0124735174812 0.0443174109184 28% => Paragraphs are similar to each other. Some content may get duplicated or it is not exactly right on the topic.
Essay readability:
automated_readability_index: 14.8 13.3589403974 111% => OK
flesch_reading_ease: 54.56 53.8541721854 101% => OK
smog_index: 3.1 5.55761589404 56% => Smog_index is low.
flesch_kincaid_grade: 11.9 11.0289183223 108% => OK
coleman_liau_index: 11.9 12.2367328918 97% => OK
dale_chall_readability_score: 8.22 8.42419426049 98% => OK
difficult_words: 65.0 63.6247240618 102% => OK
linsear_write_formula: 12.5 10.7273730684 117% => OK
gunning_fog: 12.0 10.498013245 114% => OK
text_standard: 12.0 11.2008830022 107% => OK
What are above readability scores?
---------------------
Minimum four paragraphs wanted. The correct pattern:
para 1: introduction
para 2: doubt 1
para 3: doubt 2
para 4: doubt 3
Less contents wanted from the reading passages(25%), more content wanted from the lecture (75%).
Don't need a conclusion paragraph.
Read sample essays from ETS:
http://www.testbig.com/users/toeflwritingmaster
Rates: 78.3333333333 out of 100
Scores by essay e-grader: 23.5 Out of 30
---------------------
Note: the e-grader does NOT examine the meaning of words and ideas. VIP users will receive further evaluations by advanced module of e-grader and human graders.